1. Field of the Invention
The present invention relates to a spindle motor that is installed in a hard disk drive (hereinafter referred to as HDD apparatus) or another such information recording and reproducing apparatus, to an information recording and reproducing apparatus in which this spindle motor is used, and to a method for manufacturing a spindle motor.
2. Description of the Related Art
HDD apparatuses are used in portable music players, portable telephones, and so forth, not to mention in personal computers. Therefore, HDD apparatuses and the spindle motors installed in these HDD apparatuses need to be thin and compact, and also need vibration resistance, impact resistance, and so forth.
FIG. 9 shows the configuration of a conventional spindle motor 60. As shown in FIG. 9, a cylindrical convex portion 54a is formed on a base 54. A stator core 58 around which a coil 59 is wound is attached to the outer periphery of the cylindrical convex portion 54a. A substantially cylindrical housing 52 formed by cutting is fixed to the inner periphery of the cylindrical convex portion 54a of the base 54 by crimping, adhesive bonding, or the like. The housing 52 has a stepped portion 52a on its inner periphery. A sleeve 53 is positioned and affixed by an adhesive agent on the inner periphery of the housing 52. The sleeve 53 is provided with a bearing hole 53a in which a shaft 51 is inserted in a rotatable state. A substantially cup-shaped rotor hub 56 is attached to one end of the shaft 51. A rotor magnet 57 is attached to the inner periphery of an outer peripheral wall portion 56a of the rotor hub 56 at a location opposite the stator core 58 attached to the base 54, with a constant gap in between in the radial direction.
With the spindle motor 60 configured as above, when electrical power is sequentially applied so that a rotational magnetic field is generated in the coil 59 wound around the stator core 58, the rotor magnet 57 receives the rotational force, and the shaft 51 and the rotor hub 56 to which the rotor magnet 57 is fixed rotate.
With this spindle motor 60, in the following Japanese Laid-Open Patent Application 2005-163903, for example, in between the inner peripheral surface of the housing 52 and the outer peripheral surface of the sleeve 53 are provided an adhesive reservoir and a holder for holding the two with interference. As a result, the components can be tacked without curing the adhesive agent by positioning and fixing with the holder, and the fixing strength of the two can be ensured by catching sufficient adhesive agent in the reservoir.
Also, in Japanese Laid-Open Patent Application 2007-116796, a plurality of recessed portions extending in the rotational axis direction are provided between the motor base and the sleeve. As a result, there is no deformation of the hydrodynamic groove that is formed, and the fixing strength of the two can be ensured.